Great Wall" brand glass cutting tools.
These are handheld tools used to score a shallow line on the surface of glass, which encourages it to break cleanly along that line.
The cutting wheels are typically made from hardened steel or tungsten carbide for durability and precision.
They are suitable for cutting glass in a range of thicknesses, such as 3mm to 15mm as indicated on the packaging.
Lubricants like kerosene are often used to reduce friction and achieve cleaner cuts.